From 95fe7acc86f83643bfa98d5a0da97b8457a61774 Mon Sep 17 00:00:00 2001
From: Adrian <adrian@zyte.com>
Date: Sun, 9 Aug 2026 18:14:20 +0200
Subject: [PATCH] Warn only once per request about the download warn size
 (#7963)

---
 scrapy/core/downloader/handlers/http11.py   | 7 +++++--
 tests/utils/bases/download_handlers_http.py | 1 +
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/scrapy/core/downloader/handlers/http11.py b/scrapy/core/downloader/handlers/http11.py
index 17dca5acb..3b5c08666 100644
--- a/scrapy/core/downloader/handlers/http11.py
+++ b/scrapy/core/downloader/handlers/http11.py
@@ -548,7 +548,8 @@ class _ScrapyAgent:
             txresponse._transport._producer.abortConnection()
             raise DownloadCancelledError(warning_msg)
 
-        if warnsize and expected_size > warnsize:
+        reached_warnsize = bool(warnsize and expected_size > warnsize)
+        if reached_warnsize:
             logger.warning(
                 get_warnsize_msg(expected_size, warnsize, request, expected=True)
             )
@@ -561,6 +562,7 @@ class _ScrapyAgent:
                 request=request,
                 maxsize=maxsize,
                 warnsize=warnsize,
+                reached_warnsize=reached_warnsize,
                 fail_on_dataloss=fail_on_dataloss,
                 crawler=self._crawler,
                 tls_verbose_logging=self._tls_verbose_logging,
@@ -625,6 +627,7 @@ class _ResponseReader(Protocol):
         fail_on_dataloss: bool,
         crawler: Crawler,
         *,
+        reached_warnsize: bool = False,
         tls_verbose_logging: bool = False,
     ):
         self._finished: Deferred[_ResultT] = finished
@@ -634,7 +637,7 @@ class _ResponseReader(Protocol):
         self._maxsize: int = maxsize
         self._warnsize: int = warnsize
         self._fail_on_dataloss: bool = fail_on_dataloss
-        self._reached_warnsize: bool = False
+        self._reached_warnsize: bool = reached_warnsize
         self._bytes_received: int = 0
         self._certificate: ssl.Certificate | None = None
         self._ip_address: ipaddress.IPv4Address | ipaddress.IPv6Address | None = None
diff --git a/tests/utils/bases/download_handlers_http.py b/tests/utils/bases/download_handlers_http.py
index e44f9bcb8..65244b938 100644
--- a/tests/utils/bases/download_handlers_http.py
+++ b/tests/utils/bases/download_handlers_http.py
@@ -628,6 +628,7 @@ class TestHttpBase(ABC):
             "Expected to receive 5 bytes which is larger than download warn size (4)"
             in caplog.text
         )
+        assert caplog.text.count("download warn size (4)") == 1
 
     @coroutine_test
     async def test_download_with_warnsize_no_content_length(